Which of the following words has its letters in alphabetical order?

Let's check the position index values of the constituent letters for each word option:
* Work: $\text{W}(23)>\text{O}(15)$ (Not ordered)
* Drizzle: $\text{D}(4)<\text{R}(18)>\text{I}(9)$ (Not ordered)
* Swim: $\text{S}(19)<\text{W}(23)>\text{I}(9)$ (Not ordered)
* Almost: $\text{A}(1)<\text{L}(12)<\text{M}(13)<\text{O}(15)<\text{S}(19)<\text{T}(20)$ (Perfect ascending alphabetical order)